US Patent 8664642 Nonplanar graphite-based devices having multiple bandgaps

A graphite-based device comprising a substrate with a plurality of zones and one or more graphene stacks overlaying the zones is provided. A first zone comprises a plurality of surfaces. A first surface is adjacent to a second surface in the plurality of surfaces. The one or more graphene stacks comprise a first graphene stack in the first zone. The first graphene stack comprises a plurality of graphene layers, a first of which is formed on the first surface. The first graphene layer is either planar or non-planar. A second graphene layer in the plurality of graphene layers comprises a first portion formed on a top surface of the first graphene layer, a second portion formed on the second surface and a first intermediate portion connecting the first and second portions. The second graphene layer is non-planar. The first and second graphene layers have different characteristic dimensions and different bandgaps.